Device for producing a locally defined stamped and/or printed pattern repeated at predetermined intervals on a moving web of sheet material



y 8. 1967 K. H. MARTE NSSON 3,331,319

DEVICE FOR PRODUCING A'LOCALLY DEFINED STAMPED AND/OR PRINTED PATTERN REPEATED AT PREDETERMINED INTERVALS ON A MOVING WEB OF SHEET MATERIAL Filed Sept. 5, 1964 '2 Sheets-Sheet 1 y 3. 1967 K. H. MARTENSSON 3,331,319

DEVICE FOR PRODUCING A LOCALLY DEFINED STAMPED AND/OR PRINTED PATTERN REPEATED AT PREDETERMINED INTERVALS ON A MOVING WEB OF SHEET MATERIAL Filed Sept. 5, 1964 2 Sheets-Sheet 2 United States Patent 3,331,319 DEVICE FOR PRODUCING A LOCALLY DEFINED STAMPED AND/0R PRINTED PATTERN RE- PEATED AT PREDETERMINED INTERVALS ON A MOVING WEB OF SHEET MATERIAL Kjell Halvard Miirtensson, Malmo, Sweden, assignor to AB Tetra Pak, Lund, Sweden, a Swedish company Filed Sept. 3, 1964, Ser. No. 394,215 Claims priority, application Sweden, Sept. 20, 1963, 10,283/ 63 1 Claim. (Cl. 101-291) This invention refers to a device for producing a locally defined stamped and/ or printed pattern repeated at predetermined intervals on a moving web of sheet material.

A field where the device according to the invention may advantageously be used is within that branch of the packaging industry where packages are continuously formed from a moving web of material, these packages are filled with a liquid product and sealed and every finished, e.g. tetrahedral, package unit is finally separated from the web. In certain cases it is desired that every package unit shall have a perforation or other similar weakening at a predetermined point, e.g. in the case of a tetrahedral package around one of its apices, in order that it may easily be broken open at this point, or that the package unit shall have a certain line pattern produced by printing at a predetermined point. For the production of packages having such perforations and/ or printed patterns the manufacturer has hitherto been confined to using machines which have initially been built for performing both the perforation and/ or printing of the web of material and all the subsequent operations thereon, because the perforation and/or printing devices have been too unwieldy to allow of being fitted to old machines subsequently. The device according to the invention has been designed with the aim that it may occupy a small space and comprise only a small number of parts, so that it will be possible to use it as an accessory to a machine which was not initially equipped for making perforations or the like on the packages.

The principal characteristics of the device according to the invention are that a stamping or printing tool which carries the pattern is pivotally suspended above the web of sheet material on a horizontal axle extending transversely of the web, the stamping or printing tool and the web being adjustable in relation to each other in such a way that the former can be applied to or withdrawn from the web, that a backing roll across which the web has to run is disposed with its axis at a certain distance in front of the axis of the stamping and/ or printing tool in the advance direction of the web and that the stamping or printing tool is designed in such away that a leading bottom point or edge thereof is equally spaced in front of the axis of the stamping and/ or printing tool as the backing roll axis, whereby it is achieved that the stamping and/ or printing tool, when applied to the web of mate-rial, will first meet this web with said point or edge opposite the backing roll axis and will then accompany the web in the motion thereof while at the same time performing a pivotal movement, the whole pattern being gradually stamped and/ or printed on the web.

The invention will be described below with reference to the accompanying drawings which illustrate a device embodying the invention. FIG. 1 is a perspective view of the device. FIGS. 2, 3 and 4 are a side elevation of the device at the moment of initiation of a stamping operation, at the moment when the operation is terminated, and at a still later moment, respectively.

The device includes a stamping or printing mechanism which consists of a box or cylinder 1, a slidable piston or flexible diaphragm enclosed in said box or cylinder, and a push rod 2 which is guided in the said box or cylinder "ice and which at its upper end is connected with the piston or diaphragm, and a stamping or printing tool 3 which is fastened to the lower end of the rod 2 projecting from the box or cylinder 1. The interior of the box or cylinder 1 above the piston or diaphragm can be put into communication with a hydraulic or pneumatic source of pressure medium through a flexible tube or hose conduit 4, and below the piston or diaphragm there may be provided, for example, a return spring, so that the piston or diaphragm is held in an upper extreme position with the tool 3 elevated when it is not subjected to pressure from the said source, but can be driven downwards together with the tool against the action of the spring when pressure medium is supplied at the top of the box or cylinder. The whole of the stamping or printing mechanism is pivotally suspended on a horizontal axle 5, which is mounted stationary in a machine frame, not shown, by means of a bearing 6 which is mounted on the top of the box or cylinder 1 and is offset in relation to the box or cylinder taxis.

The stamping or printing tool 3 is in the shape of a plate on the underside of which are provided, for example, perforation means, such as cutter projections 7. Where the desired perforation is to consist of an outline, for example a rectangle, the cutter projections 7 may be situated along the outer edges of the plate 3, as shown in the drawings, but it may often be more convenient to place the whole perforation pattern inside these outer edges.

The device also includes a backing roll 8 which is provided immediately below the stamping or printing mechanism on a horizontal shaft 9 parallel with the axis of the pivot axle 5 of said mechanism and mounted freely rotatable in stationary bearings (not shown) in the machine frame, to cooperate with the stamping or printing tool 3 for performing a stamping or printing operation on a web of sheet material 10 which has the direction of travel indicated by an arrow in the figures of the drawings, at right angles to the pivot axle 5. As seen in this direction of travel the axle 9 of the backing roll 8 is spaced a predetermined distance A in front of the pivot axle S of the stamping or printing mechanism and (when this mechanism occupies its vertical starting position) on the side of the box or cylinder axle opposite to the said axle 5. Furthermore, the plate 3, which is the stamping or printing tool, has its leading edge disposed at the same distance A in front of the axle 5, so that this edge, in the starting position of the stamping or printing mechanism, is situated straight above the backing roll axle 9, as shown in FIG. 2. An adjustable stop 11 is provided to prevent the stamping or printing mechanism from swinging rearwardly from the said starting position.

The operation of the device described is as follows. At a moment determined by a suitable timer of any wellknown type the box or cylinder 1 is supplied with pressure medium, the stamping or printing tool 3 is driven downwards, so that the leading bottom edge 13 thereof will engage the web of material 10 opposite the backing roll axle 9. Preferably, this bottom edge is rounded, as shown in FIGS. 2 to 4, to avoid that the web of material at the beginning will be subjected to an excessive pressure at a single point or along a single line. As the web of material 10 progresses, the tool 3 is carried along with it, the whole stamping or printing mechanism having imparted to it a swinging movement in a clockwise direction (as seen in FIGS. 2 to 4). The stamping or printing of the pattern on the Web of material thus takes place successively. When it is completed, the pressure medium is released from the box or cylinder 1, the tool 3 being retracted, so that at the following return swing of the stamping or printing mechanism to the starting position the tool will not engage the web of material 10. i

Above and transversely of the web of material and slightly in front of the backing roll 8 there is provided an inking roll 12 with which the tool 3 will come in contact when it has completed the stamping or printing operation and is about to leave the web of material at its trailing edge. Owing to the speed of the stamping or printing mechanism at this moment it will continue its swing to the .position shown in FIG. 4, so that the tool will be supplied with ink over the whole of its stamping or printing pattern. It is desirable to accomplish such inking also when the tool has to carry out a stamping operation only, because the cuts or impressions which are obained in the web of material are often diflicult to see but can be made more easily visible by being coloured.

The invention is not limited to the device described above but also includes modifications thereof. In such a modification the stamping or printing tool may for instance be suspended pivotally direct on the horizontal axle, i.e. the box or cylinder 1, with the associated diaphragm or piston, may be omitted, while on the other hand the backing roll is mounted in bearings which are movable towards and away from the stamping or printing tool under the influence of a stationary pressure box. In this modified construciton the application and the withdrawal of the tool to and from the web, respectively, is thus brought about by movement of the "backing roll at right angles to the axle thereof.

I claim:

A device for producing a locally defined pattern repeated at predetermined intervals on a moving web of sheet material, comprising a reciprocating tool with a head carrying the pattern means pivotally suspending the tool above the path of the web of sheet material on a horizontal axle extending transversely of said path, said tool having a rounded bottom edge at the forward leading portion thereof means for supporting said tool so as to be slidable at right angles to and in front of said horizontal axle, means for imparting sliding movement to said tool alternately towards and away from said web path, a backing roll for supporting the web at a point of enagagement of the tool in an advanced condition thereof with said Web, said backing roll having its axis spaced ahead of the axis of said tool when said tool is suspended in its initial normal position in the advance direction of the web a distance such that the leading point of the tool head engages the web to begin a forward stroke of the tool, said tool being adapted to be moved in tangential contact with the backing roll during said forward stroke in one direction on the pivotal suspending means to impart a printed pattern on the moving web, said sliding movement imparting means being operative to retract the tool after completing said forward stroke to thus maintain the tool out of contact with the web and backing roll as said tool is returned in a rearward stroke to initial position.

References Cited UNITED STATES PATENTS 1,291,057' 1/1919 Marks 101l03 1,360,063 11/1920 Waters 10l297 X 1,474,142 11/1923 Caplinger 101-212 X 1,695,271 12/1928 Caplinger 101-261 X 2,351,660 6/1944 Campbell 10127 2,418,213 4/1947 Winterkamp 101-4 2,497,798 2/1950 Root 101297 2,497,799 2/1950 Root 101-298 WILLIAM B. PENN, Primary Examiner. 

